The present invention relates to the field of generating pressure pulses and more particularly a method of generating and utilizing such pulses for the demolition of rock formations and the like. It is desirable to provide for the generation of repeated short rise time pressure pulses from a hydraulic accumulator. It is known to build up very high pressure to rupture a disk which very abruptly releases the pressure from the accumulator. However, the use of such a disk has the disadvantage that the disk is destroyed, and the replacement of the ruptured disk is time consuming and costly. A high pressure rock demolition pulse generator is disclosed in copending application 07/287,195 filed 12/19/88 in the name of Jack Kolle, now U.S. Pat. No. 4,863,220 issued Sept. 5, 1989, whereby pressurization of the accumulator and discharge of the accumulator is accomplished through the use of only one reusable moving part, in contrast with the non-reusable disk. While this valve was effective, we found that it was subject to severe wear on the ball and cage assembly. In addition, a significant fraction of the stored energy in the accumulator was lost through the input pilot line due to the gap between the ball and the wall of the cage.